Calling dial



April 13 1926.

, C. I. BAKER CALLING DIAL Filed March '7, 1924 Patented Apr. 13, 1926.

* UNITED sTAr s 1,580,943 PATENT OFFECE.

CLARENCE I. BAKER, 0F ELIZABETH, NEW JERSEY, ASSIGNOB TO WESTERN ELECTRIC COMPANY, INCOBPOBATED, OF NEW' YORK, 11'. Y., CORPORATION OF NEW YO CALLING DIAL.

Application filed March 7, 1924, Serial No. 697,460.

1' 0 all whom it may concern Be it known that I, CLARENCE 1. BAKER, a citizen of the United States of America, residing at Elizabeth, in the county of Union, State of New Jersey, have invented certain new and useful Improvements in Calling Dials, of which the following is a full, clear, concise, and exact description.

This invention relates to calling dials, and more specifically to calling dials of the type used in automatic telephone eX- changes for controlling the movement of automatic switches and the like.

An object of the invention is to reduce to a minimum the false operation of the shunt springs of a calling dial and 'the re sultant setting of the telephone circuit through the accidental operation of the finger Wheel. 7

These objects are accomplished by providing means permitting a limited movement of the dial before the shunt springs till are. operated to their off-normal position, and by provldlng for maintaining-the shunt springs in their olfnormal position, when once operated, until the switching opera.- tions are completed and the dial returned to its normal position. Another feature is the arrangement of parts whereby the mechanism foroperating the impulse springs of the dial is rendered more compact. a

Other features of the. invention and advantages will appear from the following description and the claims appended hereto,.reference being had to the accompanying drawings in which Fig. 1 is a plan view of the calling dial with the finger wheel and easing partially cut away so as to show the impulse mechanism more clearly; Fig. 2 is a vertical sectionalview taken approximately on line 2-2 of Fig. 1; Fig. 3 is a horizontal sectional view taken approximately on line 33 of 2 and viewed in the direction indicated by the arrows, and Fig. 4: is a. view similar to that of Fig. 3, but showing the shunt spring operating member out of normal position. Similar reference characters refer to similar parts throughout the several views.

The calling dial shown in Fig. 1 consists of a casing 10 in which the plates 11 and 12 are secured by means of a number of screws 13 On plate 11 is rigidly fastened a bushing; 14 in which the shaft is leosely 18 and for holding it inposition concentric with reference to the shaft 15.. On the lower end portion of bushing 14 there is rotatably mounted a gear23'which. has a toothed clutch portion "24 in operable relation' with its complementary clutch member 25 which is mounted on the shaft 15 and secured. thereon by means of a nut 49 and an arm 48 which is provided fora purpose which will be hereinafter described Gear 23 meshes with a pinion 26 which is loosely mounted on a spindle 27 secured on bracket 28 which is preferably formed integral'with the plate 11. On the hub portion of pinion 26 there is secured a gear 29 which meshes with a pinion 3O loosely mounted on the upwardly extending portion of bushing 14. Pinion 30 carries, at one end, an. impulse cam 31 which is made of insulating material and on theother end a wormigear 32 which meshes with the worm 33 secured on the shaft 34% of a centrifugal governor 35 which may be of any'well l nowntype-.

The shunt springs 39, a0 and 4:1 andthc nnpulse springs 3'2. and 38' are mounted on the plate 11 in the form of a: bank 8. The

functions of these springs will be understoodby reference to F. N. Reeves Patent No. 1,353,612, granted September 21, 1920,. which shows a circuit in which adial embodying this invention may be used. The terms shunt springs and impulse springs as used herein are intended to .be generic terms embracing calling mechanism operated contacts having functions equivalent to those of Reeves contacts. Theimpulse springs 37 and 38, extend from the bank in operable relation with the impulse cam 81 which is geared to operate the impulse springs once for each revolution. I11- tegrally formed with the shunt spring 40 there is provided tum-n1 42 which extends downwardly therefrem in operable relation.

member 43.

In casing there is mounted a disc 50 adapted for supporting a numbered disc which is held securely thereon by means of a removably arranged ring 52 interposcdbetween the ridge 53, of disc 50 and the numbered disc 51. The tension of the motor spring 18 may be adjusted by disengaging the disc 17 from the notches 21 of collar and rotating this disc on the shaft 15 until the proper tensionof the spring is secured.

' tion of the cam.

The operation of the dial is as follows: Supposing that it is desired to send aseries of electrical impulses through a telephone or similar circuit, 7 the movement of the finger wheel 16 toward the stationary finger stop 53 in, a clockwise direction rotates the arm 48 which moves the toothed member 45 and the. camming member 43 carried thereby in position shown in Fig; 4 for establishing contacts between the shunt springs 40 and 41 andwind the motor spring 18. But it is to be noted that due to the space between the arm 48 and tooth 54 of member 45, the finger wheel 16 and arm 48 carried thereby, are free to move a sufiiciently great angular distance inefiective with respect to the shunt spring 40 in orderto prevent the accidental setting of a selector switch in case the finger wheel 16 is permitted to re I turn to normal before the dialing operation.

The rotation of the finger wheel 16 and the clutch-member 25 carried thereby in a countier-clockwise direction, engages the clutch toothed portion 24 of gear 23 which rotates as a unit with the shaft 15 under the action of the motor spring 18. Gear 23 rotates the pinion 26 which'transmits its movement to the gear 29 through the hub portion 6. Gear 29 rotates the pinion 30 and the impulse cam 31 carried thereby for operating the impulse springs 37 and 38 at each revolu- The worm gear 32 carried by pinion 30 rotates the centrifugal governor 35 adapted for controlling the speed of the impulse cam. When the finger wheel 16 and the arm 48 reach a very small angular distance from normal inits return movement, the arm 48' engages the tooth portion 49 of member 45' for operating the shunt spring 40 at the instant the finger wheel reaches its normal position.

What is claimed is:

1. In a calling dial, an impulse mechanism, a finger wheel for actuatingsaid mechanism,'shunt springs, and means operable through the movement of said finger wheel for opening and closing said springs at different angular distances according to the direction of movement of said finger wheel.

2. In a calling dial, the combination with a casing, of an impulse mechanism, a removably arranged plate in said casing for supporting said mechanism, a linger wheel, a

vspring tensioned by'the movement of said wheel for operating said mechanism, operable shunt contacts, and a camming member operable for closing and opening saidcontacts at different angular distances with reference to the movement of said wheel in different directions.

3. In a calling dial, a casing, a removably arranged plate in said casing, an impulse mechanism arranged on said plate, said mechanism including a shaft, a finger wheel secured on said shaft, means carried by said shaft for operatively engaging said mecha nism through the movement of said wheel in one direction, shunt contact springs, and

means operable through the movement of said wheel for opening and closing said shunt springs at different angular distances with reference to the normal positiono-f said finger wheel.

4 In a calling dial, the combination of a casing, an impulse mechanism, a plate arranged in said casing for supporting said mechanism, a finger wheel, a motor spring wound by the movementof said wheelin one direction for actuating said mechanism, shunt springs, means operablethrough the movement of said Wheel for operating said shunt springs and a stop in said casing cooperating with said means for holding said wheel in normalnon-operated position.

arranged on said plate, a mechanism for operating said impulse springs, said mechanism consisting of a rotatable shaft, afinger wheel arranged on one end of said shaft, a motor spring, a gear train, a cam actuated by said gear train for operating said impulse spring through the tension of said spring, a clutch member carried by said shaft for operatively engaging said gear a train, and means operable t-hrough the move- ,ment of sald finger wheel for opening and closing said shunt springs at different angular distances depending upon the movement of said wheel.

7. In a calling dial, an impulse mechanism, said mechanism including a finger wheel, a gear train, a cam actuated by said gear train, a pair of impulse contacts operable through the movement of said cam, a speed governor for controlling the move- 10 ment of said gear train, a motor spring tensioned through the movement of said finger wheel in one direction for actuating said gear train in the other direction, shunt contacts, and means carried by said shaft for 15 opening and closing said shunt contacts in difierent angular distances upon the movement of said wheel in different directions.

beginning of said forward movement and remalning in operated position substantially until the end of said backward movement;

In'witness whereof, I hereunto subscribe my name this 29th day of February A. 1)., 1924.

CLARENCE I. BAKER. 

